About 40 "informal notes" by Kevin Brown on combinatorics: Dedekind's problem, cumulative permutation sequences, the factorial number system, Hardy and Ramanujan on partitions, solving magic squares, collecting k...

A unit that introduces elementary ideas included in probability theory, defining important words and ideas, presenting formulas for solving problems, and discussing permutations, combinations, and compound probability....

This website focuses on “magic squares” and their mathematical significance. Magic squares received their name because there are so many relationships between the sums of the numbers filling the squares. Students can...

An extensive annotated list of links to material on many-dimensional geometry.

Unsolved problems on perfect graphs, a collection for people with at least a basic knowledge of the subject. Contents include: Perfection of special classes of Berge graphs; Recognition of special classes of Berge...